121221979 has 2 divisors, whose sum is σ = 121221980. Its totient is φ = 121221978.

The previous prime is 121221941. The next prime is 121222007. The reversal of 121221979 is 979122121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121221979 - 2⁷ = 121221851 is a prime.

It is not a weakly prime, because it can be changed into another prime (121221929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610989 + 60610990.

It is an arithmetic number, because the mean of its divisors is an integer number (60610990).

Almost surely, 2^121221979 is an apocalyptic number.

121221979 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221979 is an equidigital number, since it uses as much as digits as its factorization.

121221979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 34.

The square root of 121221979 is about 11010.0853311861. The cubic root of 121221979 is about 494.9110189342.

The spelling of 121221979 in words is "one hundred twenty-one million, two hundred twenty-one thousand, nine hundred seventy-nine".